Plastic seal parts on car engine


Services: CNC Machining, EDM, Plastic Injection Molding

Part Material: TPV, PP

Mold Material: S136

Cavity: 1*4

Mold Standard: LKM

About this product

Four very small plastic parts, mainly used in car engines, play a sealing role. Since these components are of the same size, we suggest our customers to make four cavities, which can better save the cost of our customers.

The challenges of this project

Draft angles

Challenge: Because the product has many undercuts, the undercuts will affect the automatic fall off of the product, resulting in the product always hanging on the ejector pin, cannot automatically fall down.

Solution: Some products have a side of the reverse part, in some cases, if the reverse part is small, the shape and dimension accuracy requirements are low, forced ejection will not destroy the shape of the product, you can use forced ejection demoulding.

If the precision of the shape and dimension of the product is higher, or there are large convex and concave parts on the side, the side parting and core pulling mechanism must be designed. According to the different structural shape and requirements of the product, we can design sliding block, diagonal, elastic position and other mechanisms to solve the problem.


Challenge: Because the product material is TPV, the high viscosity resin will cause excessive flow resistance, increase the cavity back pressure during the mold filling process, resulting in mold parting surface clearance, and eventually form burring issue.

Solution: Our engineers in the mold design, by improving the accuracy of the mold, reduce the mold gap, improve the mold shut to solve the problem.

Line of Draw and Parting Line

The line of draw is the direction in which the two halves of the mold open and close. It defines how the part can be removed, and also shows where a parting line mark will be left over on the finished piece.

Ejector Pins

The plastic mold is covered with large and small things like needles, which is called ejector pins. The role of ejector pin in the mold is to separate the plastic products from the mold, that is, to top out the plastic mold products, make the product release smoothly, convenient to take out the product, and play a fixed role in the mold. In injection mold structure, the design of ejecting mechanism directly affects the quality of plastic products.

Injection Gate

In the design of the mold to comprehensive consideration, in the case of ensuring the quality of injection, choose a suitable way of injection. There are a lot of plastic products with strict appearance requirements, such as some digital electronic plastic accessories, the surface of the product cannot have any bad, we must take into account whether it will affect the appearance and assembly when choosing the way and position of gluing.

How It Was Made – Making The Injection Molded Parts

Step 1 Mold Design

Step 2 Mold accessories

Step 3 CNC Machining

Step 4 EDMStep 5 Wire CuttingStep 6 Mold Polish

Step 7 Mold AssemblyStep 8 Mold TrialStep 9 Sample QC

The Finished Product

Each new product design presents a unique set of manufacturing challenges. We need our engineers to keep improving on mold design, the machine shifter to be highly sensitive to data, the quality department's strict control, and a strong team to work together to complete a project.

We were able to do this because our excellent design team, experienced technicians and strict quality control system were able to provide the right design solutions in a timely manner. See below for more product development case studies. You can rest assured that when you upload CAD files for free quotes and project reviews, you will get the same manufacturing excellence applied to your next project.